Spinal implant structure and kit thereof

Abstract

The present invention provides a spinal implant structure. The spinal implant structure comprises a first part, a second part and at least one expansion arm. The second part is disposed on the horizontal orientation of the first part and does not overlap with the first part. The diameter of the first part is larger than that of the second part. One end of the expansion arm is connected to the first part, and the other end of the expansion arm is free end. The expansion arm includes a supporting arm. One end of the supporting arm is connected to the expansion arm, and the other end is connected the second part. The support arm includes a plurality of structure weakness. When the distance between the first part and the second part changes, the support arm bends from the structure weakness, thereby the spinal implant structure is expanded.

What is claimed is: 
     
       1. A spinal implant structure having a folded position and an expansion position, comprising
 a body, the body being a hollow-cored cylinder when the spinal implant structure is in the folded position, the body comprising:
 a first part; 
 a second part; and 
 at least one expansion arm, the expansion arm having an end connecting with the first part and another end being a free end; and 
 at least one supporting arm, the supporting arm having an end connecting with the expansion arm and another end connecting with the second part, 
 wherein the supporting arm comprises a plurality of weakening portions so that, in response to a change in a distance between the first part and the second part, the supporting arm bends at the plurality of weakening portions and thus drives the expansion arm to move, thereby increasing an included angle between the expansion arm and the first part, expanding the spinal implant structure, and causing the spinal implant structure to turn into the expansion position; 
 
 wherein a number of expansion arms is three, and a ratio of curvatures of the three expansion arms is higher than 1:1:1 but less than or equal to 1.6:1:1. 
 
     
     
       2. The spinal implant structure of  claim 1 , wherein the curvature of each of the three expansion arms refer to the curvature formed by an outer surfaces of each of the three expansion arms. 
     
     
       3. The spinal implant structure of  claim 1 , wherein one of the expansion arms has a curvature of 150 degrees, and the other two of the expansion arms have a curvature of 105 degrees. 
     
     
       4. The spinal implant structure of  claim 1 , wherein one of the expansion arms has a curvature of 145 degrees, and the other two of the expansion arms have a curvature of 107.5 degrees. 
     
     
       5. The spinal implant structure of  claim 1 , wherein one of the expansion arms has a curvature of 140 degrees, and the other two of the expansion arms have a curvature of 110 degrees. 
     
     
       6. The spinal implant structure of  claim 1 , wherein one of the expansion arms has a curvature of 135 degrees, and the other two of the expansion arms have a curvature of 112.5 degrees. 
     
     
       7. The spinal implant structure of  claim 1 , wherein one of the expansion arms has a curvature of 130 degrees, and the other two of the expansion arms have a curvature of 115 degrees. 
     
     
       8. The spinal implant structure of  claim 1 , wherein one of the expansion arms has a curvature of 125 degrees, and the other two of the expansion arms have a curvature of 117.5 degrees. 
     
     
       9. The spinal implant structure of  claim 1 , wherein the spinal implant structure is configured to be implanted in an implant passage of a vertebral body, and the expansion arm with the greater curvature is used for individually contacting one side of the implant passage, the expansion arms with the smaller curvature are used for jointly contacting the other side of the implant passage. 
     
     
       10. The spinal implant structure of  claim 1 , wherein the spinal implant structure has an outer diameter configured to be smaller than an inner diameter of an implant passage in the folded position. 
     
     
       11. The spinal implant structure of  claim 1  further comprising:
 a fixing screw barrel fitting inside the first part, the fixing screw barrel has an outer diameter larger than an inner diameter of the second part, and causing an end of the fixing screw barrel abuttingly connecting with the second part to fix the distance between the first part and the second part. 
 
     
     
       12. The spinal implant structure of  claim 11 , wherein the fixing screw barrel comprises a fixing portion, a fracture portion, and a removal portion, the fracture portion is located between the fixing portion and the removal portion, and the fracture portion is a weakening structure. 
     
     
       13. The spinal implant structure of  claim 11 , wherein an inner surface of the first part has a first thread portion, an outer surface of the fixing screw barrel has a second thread portion, the first thread portion matches with the second thread portion. 
     
     
       14. The spinal implant structure of  claim 1 , wherein a number of the weakening portions of the supporting arm is two, and the two weakening portions have opposite opening directions. 
     
     
       15. The spinal implant structure of  claim 14 , wherein an interior angle of one of the two weakening portions close to the second part is smaller than an interior angle of the other weakening portion after bending. 
     
     
       16. The spinal implant structure of  claim 1 , wherein a thickness of the expansion arm is gradually thinned from one end close to the first part to the other end of the expansion arm away from the first part. 
     
     
       17. The spinal implant structure of  claim 1 , wherein a shape of a cross section of the expansion arm in a long axis direction of the spinal implant structure is a wedge shape. 
     
     
       18. The spinal implant structure of  claim 1 , wherein a thickness of the supporting arm is gradually thinned from one end close to the first part to the other end of the supporting arm away from the first part. 
     
     
       19. The spinal implant structure of  claim 1 , wherein a shape of a cross section of the supporting arm in a long axis direction of the spinal implant structure is a wedge shape.